1. Field of the Invention
It is known a recording level gauge type display device, comprising several light emitting diodes distributed in a row and connected to a control circuit and to a power supply device adapted to power each diode with a same predefined voltage value The command circuit is capable of receiving an input signal and of controlling sequentially and discretely the supply of a certain number of diodes according to the input signal value, such that the number of lit diodes is representative of the input signal.
This display device is notably used in radio sets to display the frequency of a radio signal.
However, this display device is complicated.
2. Description of the Prior Art
Document U.S. Pat. No. 3,928,864 describes a recording level gauge type display device comprising a single elongated diode in the form of a column, comprising, between two power supply electrodes that extend over the length of this columns, an inorganic light emitting layer and an insulating layer that also extend over the length of this column. One of the electrodes is resistive, such that when a supply voltage is applied between the electrodes a potential gradient is formed along the resistive electrode and the diode lights up to a column height, which is proportional to its supply voltage.